<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE html
    PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
  <title>Qt 4.3: commands.cpp Example File (tools/undoframework/commands.cpp)</title>
  <link href="classic.css" rel="stylesheet" type="text/css" />
</head>
<body>
<table border="0" cellpadding="0" cellspacing="0" width="100%">
<tr>
<td align="left" valign="top" width="32"><a href="http://www.trolltech.com/products/qt"><img src="images/qt-logo.png" align="left" width="32" height="32" border="0" /></a></td>
<td width="1">&nbsp;&nbsp;</td><td class="postheader" valign="center"><a href="index.html"><font color="#004faf">Home</font></a>&nbsp;&middot; <a href="classes.html"><font color="#004faf">All&nbsp;Classes</font></a>&nbsp;&middot; <a href="mainclasses.html"><font color="#004faf">Main&nbsp;Classes</font></a>&nbsp;&middot; <a href="groups.html"><font color="#004faf">Grouped&nbsp;Classes</font></a>&nbsp;&middot; <a href="modules.html"><font color="#004faf">Modules</font></a>&nbsp;&middot; <a href="functions.html"><font color="#004faf">Functions</font></a></td>
<td align="right" valign="top" width="230"><a href="http://www.trolltech.com"><img src="images/trolltech-logo.png" align="right" width="203" height="32" border="0" /></a></td></tr></table><h1 align="center">commands.cpp Example File<br /><sup><sup>tools/undoframework/commands.cpp</sup></sup></h1>
<pre><span class="comment"> /****************************************************************************
 **
 ** Copyright (C) 2007-2008 Trolltech ASA. All rights reserved.
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** This file may be used under the terms of the GNU General Public
** License versions 2.0 or 3.0 as published by the Free Software
** Foundation and appearing in the files LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file.  Alternatively you may (at
** your option) use any later version of the GNU General Public
** License if such license has been publicly approved by Trolltech ASA
** (or its successors, if any) and the KDE Free Qt Foundation. 
**
** Please review the following information to ensure GNU General
** Public Licensing requirements will be met:
** http://trolltech.com/products/qt/licenses/licensing/opensource/. If
** you are unsure which license is appropriate for your use, please
** review the following information:
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
** or contact the sales department at sales@trolltech.com.
**
** In addition, as a special exception, Trolltech, as the sole
** copyright holder for Qt Designer, grants users of the Qt/Eclipse
** Integration plug-in the right for the Qt/Eclipse Integration to
** link to functionality provided by Qt Designer and its related
** libraries.
**
** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE. Trolltech reserves all rights not expressly
** granted herein.
 **
 ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 **
 ****************************************************************************/</span>

 #include &lt;QtGui&gt;

 #include &quot;commands.h&quot;
 #include &quot;diagramitem.h&quot;

 MoveCommand::MoveCommand(DiagramItem *diagramItem, const QPointF &amp;oldPos,
                  QUndoCommand *parent)
     : QUndoCommand(parent)
 {
     myDiagramItem = diagramItem;
     newPos = diagramItem-&gt;pos();
     myOldPos = oldPos;
 }

 bool MoveCommand::mergeWith(const QUndoCommand *command)
 {
     const MoveCommand *moveCommand = static_cast&lt;const MoveCommand *&gt;(command);
     DiagramItem *item = moveCommand-&gt;myDiagramItem;

     if (myDiagramItem != item)
     return false;

     newPos = item-&gt;pos();
     setText(QObject::tr(&quot;Move %1&quot;)
         .arg(createCommandString(myDiagramItem, newPos)));

     return true;
 }

 void MoveCommand::undo()
 {
     myDiagramItem-&gt;setPos(myOldPos);
     myDiagramItem-&gt;scene()-&gt;update();
     setText(QObject::tr(&quot;Move %1&quot;)
         .arg(createCommandString(myDiagramItem, newPos)));
 }

 void MoveCommand::redo()
 {
     myDiagramItem-&gt;setPos(newPos);
     setText(QObject::tr(&quot;Move %1&quot;)
         .arg(createCommandString(myDiagramItem, newPos)));
 }

 DeleteCommand::DeleteCommand(QGraphicsScene *scene, QUndoCommand *parent)
     : QUndoCommand(parent)
 {
     myGraphicsScene = scene;
     QList&lt;QGraphicsItem *&gt; list = myGraphicsScene-&gt;selectedItems();
     list.first()-&gt;setSelected(false);
     myDiagramItem = static_cast&lt;DiagramItem *&gt;(list.first());
     setText(QObject::tr(&quot;Delete %1&quot;)
         .arg(createCommandString(myDiagramItem, myDiagramItem-&gt;pos())));
 }

 void DeleteCommand::undo()
 {
     myGraphicsScene-&gt;addItem(myDiagramItem);
     myGraphicsScene-&gt;update();
 }

 void DeleteCommand::redo()
 {
     myGraphicsScene-&gt;removeItem(myDiagramItem);
 }

 AddCommand::AddCommand(DiagramItem::DiagramType addType,
                        QGraphicsScene *scene, QUndoCommand *parent)
     : QUndoCommand(parent)
 {
     static int itemCount = 0;

     myGraphicsScene = scene;
     myDiagramItem = new DiagramItem(addType);
     initialPosition = QPointF((itemCount * 15) % int(scene-&gt;width()),
                               (itemCount * 15) % int(scene-&gt;height()));
     scene-&gt;update();
     ++itemCount;
     setText(QObject::tr(&quot;Add %1&quot;)
         .arg(createCommandString(myDiagramItem, initialPosition)));
 }

 void AddCommand::undo()
 {
     myGraphicsScene-&gt;removeItem(myDiagramItem);
     myGraphicsScene-&gt;update();
 }

 void AddCommand::redo()
 {
     myGraphicsScene-&gt;addItem(myDiagramItem);
     myDiagramItem-&gt;setPos(initialPosition);
     myGraphicsScene-&gt;clearSelection();
     myGraphicsScene-&gt;update();
 }

 QString createCommandString(DiagramItem *item, const QPointF &amp;pos)
 {
     return QObject::tr(&quot;%1 at (%2, %3)&quot;)
         .arg(item-&gt;diagramType() == DiagramItem::Box ? &quot;Box&quot; : &quot;Triangle&quot;)
         .arg(pos.x()).arg(pos.y());
 }</pre>
<p /><address><hr /><div align="center">
<table width="100%" cellspacing="0" border="0"><tr class="address">
<td width="30%">Copyright &copy; 2008 <a href="trolltech.html">Trolltech</a></td>
<td width="40%" align="center"><a href="trademarks.html">Trademarks</a></td>
<td width="30%" align="right"><div align="right">Qt 4.3.5</div></td>
</tr></table></div></address></body>
</html>
